1. Field of the Invention
The present invention relates to a high-strength aluminum alloy having an improved strength by surrounding a homogeneous fine amorphous phase in the network form by crystalline phase.
2. Description of the Prior Art
Japanese Patent Laid-Open Nos. 260037/1991 and 41654/1992 already disclosed high-strength aluminum alloys wherein an amorphous phase was present together with a crystalline phase. These alloys are high-strength alloys comprising an amorphous matrix and fine crystalline particles dispersed therein. In these alloys, however, the volume percentage of the crystalline phase is less than 40%, and there remains room for remedying the instability of the amorphous phase constituting the matrix and the brittleness inherent in that phase. Further, since they have a structure mainly composed of an amorphous phase, they unavoidably contain a large amount of additive elements comprising transition metals and rare earth elements, which gives rise to an increase in the density.
In conventional high-strength alloys consisting of an amorphous phase and crystalline particles dispersed therein, the total volume of the crystalline phase is up to 40% by volume with the major part of the balance consisting of an amorphous phase. In these alloys, the volume of the crystalline phase is limited to 40% or less because when it exceeds 40%, harmful intermetallic compounds are formed. In the present invention, quasicrystals, which are a kind of intermetallic compound, are finely dispersed in an amorphous phase to prevent the occurrence of other harmful intermetallic compounds in the crystalline phase, thereby providing a material having excellent toughness and strength.